Poor Customer service at Waterfall Mall

I have taken my kids to use voucher they received as a gift. Trying to use this vouchers our cashier first have a conversation with the client in front of me , being the only cashier available wasting a line full of people's time. Then afterwards having a conversation with another person while attending to my sale, not listening to me at all as he is having a conversation with someone else using my cash and leaving a R30 on my voucher after I was waiting for my change as requested. When I ask him about he, he tells me it is not his problem it is on the voucher now i can take something off the shelf. Poor customer service!